Variable sprocket-gear.



' No. 7l2,985. Pafented Nov. 4, I902.

w. o. WANSBROUGH.

VARIABLE SPRUCKET GEAR.

(Ami. t fildl-b 18 1902 4 Sheets-Shut (No Model.)

n IS FEYiRS so, Pnnro-uma, wnsums'mu n c No. 7|2,985. Patented Nov. 4,I902.

W. D. WANSBBOUGH.

VARIABLE S'PROCKET GEAR.

(Application filed Feb. 18, 1902.)

4 sheets-sheet 2.

(No Model.)

NGTON, a. c.

T: NORRIS Pains 50. PH

' Patented Nov. 4, I902. W. D. WANSBROUGH. VARIABLE SPROCKET GEAR.

(Application filed Feb. 18, 1902.1

4 Sheets-Sheet 3.

'(NO Model.)

FIG- 5- III Azlzz A VII/I/l/l/ld 1 mm" WASHIN No. 7I2,985. Patented Nov.4, I902.

w. n. WANSBROUGH. 4

VARIABLE SPRUCKET GEAR.

(Application filed Feb. 15, 1902' 4 Sheets$heet 4.

(No Model.)

UNITED STATES;

PATENT OF ICE.

' WILLIAM DYSON WANSBROUGH, or LINCOLN, ENGLAND.

VARIABL sP ooKET-c EAR.

SPECIFICATION forming part of Letters Patent No. 712,985, dated November4, 1902. Application filed February 18, 1902, Serial No. 94,62 (Nomodel.)

clear, and exact description of the invention,

such as will enable others skilled in the art to which it appertains'tomake and use the same. p

This invention relates to a new or improved m ultiple-speed gear-wheelof the kind wherein a flexible divided chain-ring having overlappingextremities is expanded or contracted while carried against a circularplate, so as to provide a higher or lower gear, the'object of thepresent invention being'more particularly to provide new or improvedmeans for expanding and contracting the chain ring and of sucha naturethat it is rigidly held at'all points from its minimum to its maximumdiameter, and vice versa, and in this manner to provide severaldifferent gears from the highest to the lowest corresponding to thedifferent diameters in which the chain-ring is employed. In order thatthis invention may be more fully understood, Iwill now proceed todescribe same with reference to the accompanying drawings, in which"Figure 1 is a diagrammatic side view of a chain-wheel constructedaccording to this invention. Fig. 2 is a detail vertical section throughthe locking-plate l, shown in Fig. 1.} Fig. 3 is a partial section takenon linezcx'in Fig. 4. Fig. 4 is a sectional plan view of the chain-wheelfrom below. Fig. 5 is a section taken on line y y in Fig. 1. Fig. 6 is adetail view of one of the pins's. Fig. 7 is a detail side View of theouter plate, and Fig. 8 is a section-taken on line BB in Fig. 7. Fig. 9is a detail side View of the inner plate, and Fig. 10 is a section takenon the line 0 O in Fig. 9. Figs. 11 and 12 aredetail views of the meansfor operating the sliding. plates. v In carrying this inventionintopractical efiect and as sh'own'in the drawings I provide a gear-wheelcapableof being employed for giving seven different gears and consistingof a flexible divided chain-ring a, formed with teeth in the usualmanner around the greater part of its circumference and having a plainreduced part b forming a bridge between the points a and d when thechain-ring is in the expanded position, but sliding under the part (1when in the contracted position. The chainring is formed with eight lugse and a ninth lug f, and through the eight lugs e studs 9 are passed,which are preferably screwed and riveted in place, and each stud carriestwo rollers g. The chain-ring is carried against two superposed plates h't', formedwith overlying curved slots, the outer'plate 71 beingfurnished with nine slots 1 to 9 and the inner plate 't' with nine slots1 to 9, which correspond to the nine points of attachment ofthechainri-ng. The outer plate his formed in two parts secured togetherandwith a flanged edge It, and the inner plate 2' fits into the same,while the studs and rollers forming'the connections of the chain-ringpass through and are contained within the slots of both plates, while asthe ninth slot in each plate if formed in the same manner as the firsteight slots would intersect some of the said slots these ninth slots areformed more toward the center of the plates, as shown, and the ninthpoint of toothed quadrant 70, with which engages a toothed pinion orwheel formed integrally with or secured to a star-wheel 70 which as thechaine'wheel revolves may come into contact with a pin, either 1- or s,projecting from a fixed part of the frame of the machine, so that it,together with the pinion k, may be turned one tooth at a time, so as toturn the inner plate t' through the spaceof onetooth of the quadrant k,the"star-wheel being operated either from the top or'the bottom,'according to the direction in which it is required to' be revolved.The. said star wheel and pinion are provided with a shaft or spindle,

which is journaled in the plate h, as shown in Fig. 2.

' The outer plate It and the inner plate tare normally locked togetherby a sliding locking-plate Z, which is guided and secured betweenrollers m, carried by the outer plate 71, and which is arranged in anopening, or perforation t" in the inner plate. This sliding plate has aforked upper extremity Z sliding over the central axle A and at itslower extremity is furnished with teeth a, normally engaging the toothedquadrant k, in which position it is kept by the spring 0, while the saidplate is formed with a bridge-piece Z provided with a curved slot Z asshown.

Before the inner plate 1' can be turned for altering the gear it isnecessary for the locking-plate to be raised so as to free it from thetoothed quadrant 7t, and for this purpose and also for turning thestar-wheel I arrange within the casing 1), close to the bottom bracketof the machine, two superposed sliding plates, each provided with a slotp, which cross at right angles, as shown at Fig; 2, and through theseslots a pin or roller p works, which is connected with the sliding arm19 The arm 19 enters a cylindrical casing q and is normally retainediuthe forward position by a spring q, but may be drawn within thecylindrical casing q through the medium of a suitable connection (1 Inthis manner by drawing forward the pin or stud p or allowing it to beforced inward by the action of the spring q one or other ofethesuperposed sliding plates may be forced toward the chain-wheel, or theymay be both held in the intermediate position, as shown in the drawings.One of the superposed sliding plates is formed with a projecting pin a,designed to operate the star-wheel k from the top, and also with a pinT, designed to lift the locking-plate Z, as hereinafter described, whilethe second sliding plate is provided with a projecting pin 3, designedto operate the star-wheel k from the bottom, and with a pin 8 forlifting the lockingplate Z.

To expand the chain -ring, the sliding plate provided with the pins 3 sis brought forward, so that as the chain-wheel passes the same the pin 5enters the curved slot Z in the bridgepiece Z of the locking-plate,lifts it out of engagement with the toothed quadrant 7c, and retains itin the raised position,while the starwheel 10 bystriking against the pinsis turned one tooth, thus operating the pinion 7c and turning thequadrant It one tooth, when the pin 3 passes out of the slot Z and thelocking-plate again engages the toothed quadrant 76 and locks the twoplates together for the remainder of the revolution. In a like mannerfor reducing the gear the plate provided with the pins 0' r is broughtforward, so that as the chain-wheel passes the same the pin 1" entersthe slot Z and raises the locking-plate, while the star-wheel isoperated from the top by the pin 1*, the pin 7* then passing out of theslot and allowing the locking-plate to again engage the toothedquadrant. In Fig. 1 these pins are diagrammatically shown in dottedlines.

In order that the plate carrying the pins 8 3 may be automaticallyforced back to allow the star-wheel to pass Without being operated whenthe chain ring is fully expanded, a curved plate 25 is pivoted to theinner plate 1', as at t, Fig. 1. This plate is formed with an upstandingedge to, having an inclined part u running down to the face of theplate, while a pin 25 projects into a slot t formed in the back plate h.The greater part of the slot 25 is concentric with the center of theplate and in the first six positions of the chain-ring retains the platein the raised position, as shown, so that the pin s in passing escapesthe upstanding edge u; but at the seventh position of the chain-ring,when it has reached its maximum diameter, the extremity t of the slot 5forces the pin 25 and with it the plate 25, outward from the center ofthe wheel, so that as the wheel revolves the inclined part to of theupstanding edge u strikes the pin 3 and forces it and the sliding plateof which it is part back, so that the star-wheel passes in front of thepin and is not operated by it. In a like manner for preventing thestar-wheel being operated after the chainring is fully contracted theplate '0 is pivoted, as at c, to the back plate h and is formed with anupstanding edge '0 having a sloping or inclined extremity c This plateis operated by a pin 10, engaging a slot w, formed in a plate w rivetedor suitably secured to the inner plate 11, Figs. 1 and 5. The greaterpart of the slot w'is concentric with the center of the wheel and keepsthe'plate v in the raised position for the first six changes, so that asthe wheel revolves the upstanding edge 1: escapes the pin 1- in passing,which is then free to operate the star-wheel; but upon the seventhchange being made when the chain-ring is fully contracted the extremityw of the slot 10 forces the pin w, and with it the pivoted plate 12,outward from the center of the wheel, so that as the wheel revolves theinclined part 22 of the upstanding edge v comes into contact with thepin r and forces the latter and the plate of which it forms a part backand allows the star-wheel to pass without being operated.

The superposed sliding plates carrying the pins 5 s and r r are operatedby drawing back the roller 19 by means of the connection (1 ashereinbefore stated, and this may be effected by means of aconveniently-arranged hand-lever or in any other convenient and suitablemanner, a convenient means to this end being shown in the detailed viewsFigs. 10 and 11. According to this arrangement within the top of thehandle-bars a; a tube 11;, capable of a partially-rotary and verticalsliding movement, is arranged and furnished with a knob 0: by means ofwhich it may be revolved. In the outer tube 1 an inclined slot y isformed, provided with three indents or catches 3 1 while theinner tubeis provided with a pin m passing through the slot 1 and designed toengage in the notches 11 g g The inner tube 00 is provided with aprojecting pin 2, passing through a slot z, formed in the tube y atright angles to the slot y and to the pin 2. The otherextremity of theflexible connection g is secured so that by revolving the inner tube 00by the knob 01 the connection (1 is drawn forward and may be secured inany one of the three positions indicated at g g g which correspond withthe three positions of the roller p operating the sliding plates-that isto say, with the roller 19 fully forward and under the action of thespring q in the central position and fully back.

Having now described my invention, what I claim as new, and desire tosecure by Letters Patent, is

1. In an expansible wheel, the combination, witlra flexible divided ringprovided with a series of laterally-projecting pins, of two superposedplates provided with slots which cross each other and engage with thesaid pins, and means for revolving one of the said plates relative tothe other to adjust the said ring, substantially as set forth.

2. In an expansiblewheel,thecombination, with a flexible divided ringprovided with a series of laterally-projecting pins, of two superposedplates provided with slots which cross each other and engage with thesaid pins, a retractible locking device normally connecting the saidplates, and means for revolving one of the said plates relative to theother when the said locking device is retracted, substantially as setforth.

.3. In an expansible wheel, the combination, with a flexible dividedring provided with a series of laterally-projecting pins, of twosuperposed plates provided with slots which cross each other and engagewith the said pins, one of the said plates being provided with a toothedsegment, a toothed pinion and a star-wheel secured together andjournaled in the other said plate, said pinion engaging with the saidsegment, and a tappet for the said star-wheel to engage with as the saidplates are revolved, whereby one plate is revolved relative to theother, substantially as set forth.

4. In an expansible wheel, the combination, with a flexible divided ringprovided with a series of laterally-projecting pins, of two superposedplates provided with slots which cross each other and engage with thesaid pins, tappet mechanism operating to revolve one of the said platesrelative to the other step by step at each revolution of the saidplates, and means for throwing the said tappet mechanism out of actionautomatically at prearranged points, substantially as set forth.

5. In an expansible wheel, the combination,

with a flexible divided ring provided with a series oflaterally-projecting pins, of two superposed plates provided with slotswhich cross each other and engage with the said pins, one of the saidplates being provided with a toothed segment, a toothed pinion and astar-wheel secured together and journaled in the other said plate, saidpinion engaging with the said segment, a retractible locking devicecarried by the last-said plate and normally engaging with the saidtoothed segment, and tappet mechanism operating to retract the saidlocking device and partially revolve the said star-wheel at eachrevolution of the said plates, substantially as set forth.

6. In an expansible wheel, the combination, with a flexible dividedring, and mechanism for expanding or contracting the said ring step bystep as it revolves; of plates provided with tappets which operate thesaid mechanism in either direction according to the positions of thesaid tappets, said plates being also provided with slots arranged at anangle to each other, and an actuating-rod which is operatively connectedwith the said slots so that the said plates are moved laterally of thesaid divided ring in opposite directions so as to place one or the otherin action, substantially as set forth.

In testimony whereof I afflx my signature in the presence of twowitnesses.

WILLIAM DY S0l\ WANSBROUGH.

Witncssesr JAMES ODAM, O. W. PAULGER.

